Hybrid thermal management of solar photovoltaics using gas and liquid channel cooling with numerical and experimental analysis

Abstract

With the rapid development of social productivity, the human demand of energy consumption is significantly increased. Solar photovoltaic has become an essential technology for power generation instead of fossil fuel during the past decade owing to the abundant existence of global solar resource. Unfortunately, the photovoltaic panel suffers from an inevitable issue of 0.4 %-0.5 % reduction on solar energy to electricity conversion efficiency when its temperature is raised up by 1 ℃. In addition, when the photoelectric conversion efficiency of solar photovoltaics drops down, an increased amount of waste heat is generated, further deteriorating the corresponding thermal issue especially during summer season. The traditional thermal management approach of solar photovoltaic applying individual gas or liquid as heat transfer fluid has the following obvious shortcomings: low thermal conductivity and specific heat of gas with limited heat absorption; high viscosity of liquid with high pressure drop and pump power. Facing these challenges, the current work presents a hybrid gas and liquid thermal management technology of solar photovoltaic with designed fluid flow channels. Consequently, the back panel of solar photovoltaic can be cooled down by liquid cooling flow, while its front surface temperature is simultaneously dropped down through gas blowing flow cooling process. When a gas blowing flow of 4.5 m/s and liquid cooling flow of 0.08 m/s are applied at 20 ℃, the average temperature of solar photovoltaic under a solar irradiation of 1000 W/m² dramatically decreases from 66.5 ℃ to 38.8 ℃ by 41.65 %. Meanwhile, the corresponding output power of solar photovoltaics is improved from 0.658 W to 0.942 W by 43.16 %. Specifically, the average temperature of solar photovoltaic using hybrid gas and liquid channel cooling is decreased by 9.7 ℃ and 5.7 ℃ in comparison to applying individual gas channel cooling or liquid channel cooling, respectively. The current work paves a promising approach for solar photovoltaic thermal management, which can significantly ameliorate its power generation performance in practical applications.